FIG. 5.

Summary of the in vivo mRNA-degradative activities of wild-type and mutant Vhs polypeptides and their abilities to bind eIF4H and eIF4AII. The structures of the wild-type and mutant Vhs polypeptides are diagrammed on the left. For deletion mutants, the Vhs residues included in the mutant proteins are indicated. For each point mutant, the location of the altered residue is indicated by the vertical line above the bar representing the protein. The in vivo mRNA-degradative activity of each Vhs protein is shown in the column immediately to the right of the diagram. This was assayed in transfected cells for all of the alleles and during virus infections for wild-type Vhs and the mutants K(1-382), Vhs ΔSma, and T214I. ++, wild-type activity; −, no detectable mRNA-degradative activity. The middle column indicates whether a Vhs protein binds (++) or does not bind (−) eIF4H in the yeast two-hybrid system and in GST pull-down assays. These data were reported previously (18). The right column indicates whether a Vhs protein binds (++) or does not bind (−) eIF4AII and summarizes the data shown in Fig. 4.